When a disc brake is engaged, the pressing of the pedal by the driver is converted to hydraulic pressure through a booster and a master cylinder so as to transmit the hydraulic pressure to a caliper. Then the caliper presses a disc fixed with pads utilizing the hydraulic pressure, thereby generating a braking force.
However, in conventional brake systems, rattle noise will frequently occur when an automobile runs over a rough terrain. Rattle noise is generated from the impact of the movement of two or more metal components when they collide by external forces. In the conventional caliper, rattle noise is generated when the components such as the caliper housing, the shoe and the mounting bracket collide due to the vibrations caused when the automobile runs over a rough terrain.
Conventionally, in order to reduce this rattle noise, various measures have been researched. Among the methods, there is one in which the caliper components are subjected to smaller tolerances to improve the precision. In this method, however, the improvement of the precision is accompanied by an increase in the manufacturing cost, and defective products are frequently generated. Accordingly, this method has not been effective. Further, when the caliper is used for a long time, the actuation parts of the components wear out, thereby regenerating the rattle noise.